Concocting constructs

Here is a small part from TERATOGENICON, the ultimate monster generator! If you like it, consider acquiring the book on DTRPG. I wrote this post before publishing the book, so some of the text has been update. The tables and pages you see below are exactly as presented in the book. 

(The images are copyright WotC, as far as I can tell, and are not included in the book - which is lavishly illustrated by Rick Troula!)

Construct varieties

Golems – artificial humanoids created by magic - are iconic and simple. Their main distinction is the material from which they are crafted – clay, coal, iron, flesh, gemstones, marble, ceramic, stained glass, etc. Animated objects such as a flying sword or self-moving suits of armor (or furniture!) are even simpler. However, there are other types of constructs: steam-powered spiders, plastic spheres with flamethrowers, killer vehicles, and so on. You can skip some or most of the tables if you want to keep your construct simple.

Habits, diet and habitat

Constructs can be found anywhere their creators want them: guarding riches, working in factories, transporting goods, and so on. Their habits, likewise, are usually programmed in creation.

Since constructs are similar to machines, most of them can live regardless of food, drink, sleep and even air, but rely on a different power source (see below).

Clever artificers often put golems and other constructs near power sources so they can constantly refuel and regenerate, or even build traps that will help constructs while hindering invaders.

Traits

A typical construct has the following traits:

Size: any.
Alignment: Unaligned.
Abilities: good Strength, Constitution; bad Charisma, Intelligence.
Resistances/Immunities: constructs are usually resistant to poison, psychic, and many other types of damage (including nonmagical weapons that aren’t adamantine), depending on what they’re made of (and their power source), and immune to being charmed, exhaustion, frightened, paralyzed, petrified, poisoned. Magic resistance is also common.
Senses: Darkvision.
Languages: Constructs understand the languages of its creator (if any) but most cannot speak.

Artificial faces

No matter the form they take, most constructs cannot speak and thus have no mouths. Many lack noses and ears too, using magic or other means to perceive reality. Golems and other constructs made to resemble people may have lips that do not move and ears that do not work. However, many constructs with faces have eyes – usually two or a single big one, often glowing – made of glass, jewels or other materials that are really used for sight.

Appearence & Powers

Constructs, like any other apparatuses, may take any form their creator can fathom. Therefore, there is no reason why a construct cannot have three legs, five eyes and multiple antennae. However, since they are usually built by anthropocentric minds, the common construct is shaped like a person or something resembling a person (a cube with arms and legs, for example).

Shapes. Many constructs have humanoid appearance. Other look like strange, mechanical animals, or armored vehicles. Some constructs are just animated objects, while other are piles of bones, weapons, chains, etc. You can roll again in this table multiple times if you wish, generating lower limbs, upper limbs and head (for example, a construct might have tracks, four arms, and spherical head).

Power source. Many constructs are moved by magic and might be damaged or stop functioning if subjected to antimagic fields or other magic-destroying effects. Other, however, function like machines, and must consume petrol, electricity, etc., periodically. A few have internal generators that are hard to disrupt, and some are biomechanical, using normal food for sustenance.

Materials. A construct may have various resistances and vulnerabilities determined by the materials from which it is made, although some are specially reinforced to avoid the most obvious weaknesses.